My Mollies are all fine thank goodness.  -01/30/08
<Good.>
This morning when I woke up I sat to watch my fish.
<Ah yes! Best start to the day...>
I noticed that one of my males was injecting his anal fin into one of my females. He is also sniffing her under belly. From my research I learned that means the female is pregnant.
<That's the theory, anyway. The anal fin is effectively a penis, and used to direct a packet of sperm into the female where the eggs will be fertilised.>
I also noticed that he was also sniffing the other females' under belly.
<I'm not sure 'sniffing' is the word here, more likely just looking to check she's a she and not a he.>
Did he make those females pregnant too?
<Almost certainly.>
One thing I think is out of the ordinary is even though he isn't near a female or injecting a female he keeps moving his anal fine back and forth.
<Completely normal.>
What is he doing?
<Enjoying himself.> Great website, Karleigh
<Cheers, Neale.>

Mollies being panicked to see people... 12/30/07
Dear Neale,
<Kathy,>
I have two molly tanks (both are about 38 gallon). In one of them are 9 bigger mollies. They used to be very happy to see me come near their tank knowing that I am going to feed them. But recently they become very scared of people (almost panicked to see any movement I make). I am not quite sure what caused such big change in their behaviour.
<Hmm... water quality/chemistry changes can make fish nervous, and such behaviour is one of the best early warning signs of such troubles. In addition, check for things like sources of noise as well as the loss of hiding places, e.g., if you've cut back the plants or moved the rocks about.>
I have to move slowly when walking towards the tank. They all hide in one corner... Until they see some food floating do they slowly come out to eat.
After the meal, they again hide themselves if I am still around.
<Odd. I have to ask: are they in freshwater or brackish? Mollies are sensitive to low pH, low hardness, and high nitrate, and adding marine salt mix, even at fairly low doses, will help here. Common aquarium salt will detoxify nitrate, but obviously doesn't do anything to raise the hardness or pH.>
The orange molly in that tank is sort of aggressive. She always chases away every fish. But she has been in that tank lone time. This change just
started a week ago. Do you have any suggestion as to what I can do to find out the cause or correct the situation?
<Mollies do tend to be aggressive; this is a real problem with these fish, and one not a lot of people are aware of. In any case, there really aren't any "fixes" beyond [a] adding more females to dilute aggression and [b] providing more hiding places to break up the line of sight. Floating plants are especially good, but things like clay flower pots and tall plastic plants are great too.>
Thanks for your time and wish you & your family a happy & prosperous new year of 2008!
<And likewise to your own kith and kin!>
Kathy
<Cheers, Neale.>

FW, ammonia, Molly size Qs   11/28/2007
Hi-
<Howdy>
I am a beginning aquarist. I bought 1 platy and 2 mollies (Silver and Dalmatian) to start my 10gallon tank. I didn’t have an ammonia test at the time (stupid I realize now) and the mollies quickly developed ich and died.
The platy is still alive. I decided that I would just keep the platy for now, wait a month, or until the cycle begins and then gradually add more fish. My sister in effort to be nice to me bought me 1 HYPERLINK
"http://www.liveaquaria.com/product/prod_Display.cfm?pCatId=1055" Black Lyretail Molly, 1 Creamcicle Lyretail Molly, 2 Zebra Danios and a sail as a surprise for me. I wasn’t ready for that many fish- but now I have them. I have read many times that zebra danios are to be kept in groups of 5 or more. Should I buy more Zebras?
Would that be overcrowding my tank?
<I would hold off on adding more Danios... As you state... it's getting crowded, and your livebearers may well have babies>
Also, how big do the Creamcicle and Black Lyretail Mollies get?
<In such a small tank... likely about two inches in length. In larger systems, about twice this>
I have been reading a lot of websites and it seems that everyone has a different answer (especially with the Creamcicle one).
<You can look up the names under the word: Mollienesia... the genus... and see that various species, likely sphenops in this case, do grow to larger sizes in bigger settings>
I have decided to do frequent water changes to counteract the huge ammonia spike. Is this the right thing to do?
<Is one way to go... Please read here: http://wetwebmedia.com/FWSubWebIndex/fwn2cycfaqs.htm
and the linked files above.>
Help!
Sincerely,
Bea
<Bob Fenner>

Molly Flashing  11/28/2007
Hi. I have a 10 gallon aquarium that I use for Molly fry. I've noticed that the fry like to bounce off the rocks in the tank. They're not rubbing their bodies, just a quick rub of the head area. Most of the fish in the tank do this at some point. They all appear healthy, are growing and feeding vigorously. We have only lost two babies out of approximately 50 that have passed through the tank since July. Is this behavior normal or a sign of a parasite? Thanks, Joyce
<Hello Joyce. Are you adding marine salt mix to the aquarium? And what's the water chemistry? Mollies (and indeed most other fish) scratch their bodies when they are irritated. Sometimes this can be a sign of illness, specifically parasites that attack the skin and/or gills. But it can also be an indication of water chemistry issues, particularly excessively low or high pH levels. Just to recap, Mollies need very hard (ideally over 20 degrees dH) water and a pH of not less than 7.5 and ideally around 8.0. While not all Molly keepers agree, there's a widely held view that adding marine salt mix to the aquarium is beneficial. Wild Mollies are common in brackish water habitats, and when kept without salt in the water it is common (if not universal) that Mollies become more sensitive to infections such as Finrot and fungus. Salt also reduces the toxicity of nitrate, which Mollies appear to be extremely sensitive to. Marine salt mix (as opposed to generic aquarium or tonic salt) contains carbonate salts that raise the hardness and prevent acidic conditions in the aquarium, and this also has a dramatically beneficial effect on Molly health. From my experience, the vast majority of instances where people have Molly problems, those people are keeping them in tanks without marine salt mix. I'd recommend adding 3-6 grammes of marine salt mix per litre of water, and then seeing how your fish do. Cheers, Neale.>

Re: Molly Flashing 11/28/07
Hi Neale. Thanks for replying. I guess I should have listed the water conditions in my first email. All levels are good, (PH around 7.9), our
water is naturally very hard and alkaline.
<Excellent.>
We do 20% water changes once a week.
<Ramp that up to at least 30% per week and ideally 50%. Mollies do not like nitrate, and it seems to be one triggering factor being ill-health.>
I've heard that Mollies prefer saltier water, but we have two small Corys in with them, so don't want the Corys irritated.
<Fundamentally Mollies and Corydoras can't be mixed. End of story. It's a shame people sell Mollies as "community fish" because they're not.>
What has me curious is that none of the fish seem stressed or sick. They don't rub, just bounce off their heads. The two five month old males that are in the tank are gorgeous and lively, but they too flash off the rocks once in a while. I'm thinking if it was a parasite or illness, these fish should show some sign of it by now.
<I agree, but what you're describing simply isn't normal. Hence the need to try and narrow down the possible causes. Parasites on the gills (typically Ick or Velvet) plus improper/fluctuating pH are the classic causes of "flashing" behaviour.>
So the water conditions sound more likely, even though the numbers are good.
<Do check the ammonia and nitrate levels, if you can. While nitrite is the thing people usually check first, with good reason, nitrate especially is something that you have to watch with Mollies.>
Hmm, will have to investigate that possibility more carefully. Thanks for your help. Joyce
<Good luck, Neale.>

Att Neale: An observation about Mollies, beh.  10/16/07
Hi Neale!
<Hello Audrey,>
I read your answer to the person who had questions about Mollies. This person had a concern that one of his Mollies tilts slowly until it's facing up. You expressed a concern that there might be a water quality issue.
<Not so much a concern as a statement that Sailfin mollies can supplement ordinary breathing by gulping an air/water mixture at the surface. See here at the Florida Museum of Natural History: http://www.flmnh.ufl.edu/fish/Gallery/Descript/SailfinMolly/SailfinMolly.html. , under "Habitat".>
I don't doubt your knowledge (so much more extensive than mine!) but I have an observation to contribute.
<Very good...>
I've seen the tilting upwards in a lot of new Mollies. Mine didn't do it anywhere close to the surface, so I doubt they were trying to breathe, and they were in an established tank. Most of my Mollies stopped doing this after a few weeks. One never stopped. Some never displayed the behaviour. They just suddenly stop swimming, slowly tilt upwards until they're completely nose up, then just as suddenly start swimming normally again. It used to totally freak me out.
<Interesting.>
Mollies are constantly skimming the surface, but when they do it they're horizontal. I've never seen one doing it nose up (except when fighting for a piece of food, of course). If they were trying to breathe, I'd expect them to position themselves horizontally just under the surface and skim (their mouth is kind of pointing up already, so that's a natural position).
<Hmm... not sure. To use the surface layer of water, the Molly needs to tilt slightly upwards, simply because the mouth is somewhat lower than the top of the head. It's the top 1 mm of water they need, because that's where the oxygen exchange occurs. When they're feeding, Mollies adopt a variety of orientations. They have skulls and jaws modified for grazing algae, and when doing this orient themselves so the jaws can scrape flat surfaces. They also eat insect larvae, and this is where the upwards tilt of the mouth is useful, for getting mosquito larvae at the surface.>
I'll tell you about my troubles with illnesses in another email. I think I might *finally* have a clue about what's happening to my Mollies. And I have pretty gross pics to show you (they will make a nice addition to the illness pages).
<Ooh, what fun!>
Enough babbling for now. Have a nice day!
<Thanks, and you too.>
Audrey
<Cheers, Neale>

Molly Behavior  8/5/07
Hello again! It was a long time I didn't ask a question.
Can you please help me in my problem about my mollies. I have 2 golden dust molly and they are both female the problem is one of them attack the other one, also in my 2 balloon female molly. The stronger one (I guess) is attacking the weaker. Is this only mean I need a male for them?
Also I saw small black spots in their body, and seems they are scratching in the gravel. Is this a disease, how can I prevent it?
Please reply soon, I'm so worried about them. Thanks
<Greetings. Mollies are notorious for bullying one another, especially when kept in too-small an aquarium. There's not much you can do about it except increase the size of the group. This assumes you have the space in your aquarium for them. It's usually the males that are bullies, so what you are reporting is unusual. Adding a couple more females would be the best thing. Adding a male wouldn't help at all! Black spots are typically associated with infections of external lice, flukes, and worms. The standard way to treat this would be using an anti-fluke medication from your retailer. However, since you're keeping mollies, an alternative approach worth considering is moving them to a brackish water aquarium at 25-50% seawater salinity (SG 1.005-1.010). You could also raise the salinity in the existing aquarium over a few weeks to allow the filter to adapt. The salty water should shift any external parasites quite effectively, especially at the higher end of the salinity range. Maintaining mollies in brackish water will benefit them in many other ways besides, and is in my opinion by far the most intelligent way to keep these fish. Cheers, Neale>

Balloon Belly Molly Question, beh.   7/26/07
Hello. I am rather concerned about a balloon belly molly I purchased today.
She seems to be having some kind of equilibrium problem. She swims frequently, but rather awkwardly and seems to have to try a bit too hard to stay lower in the tank. It almost seems like she is over inflated at times but then she'll do an odd nose dive and I get even more confused. She has been eating and defecating normally and shows no outer signs of parasites. I cannot tell if she is pregnant because of her coloring. Could be some kind of parasite issue or a swim bladder problem? Or if it is just a quirk or something explained by pregnancy that I shouldn't worry about? I isolated her several hours after introducing her to the tank, if that helps. Thanks!
<Ave! Unfortunately, what you describe is rather common among balloon mollies as well as "balloon" shaped goldfish, and for the same reasons -- inbreeding to produce these deformed body shapes has messed up what evolution achieved in terms of swimming ability. It doesn't take much to totally throw them off balance, and things like constipation, which moves the centre of gravity, cause swimming ability to diminish greatly. So, let's review: Mollies are herbivores in the wild and in the aquarium. They need greens (i.e., fibre) much more than they need standard fish food. (Standard fish food is about as healthy for them as feeding t-bone steaks to a sheep would be.) Double-check you're using an algae-based livebearer flake food, for example one based on Spirulina. Also check your offering fresh greens like sliced cucumber, blanched lettuce, spinach, squashed tinned peas, and so on. Actual algae from a pond or as Sushi Nori is also very helpful. Meaty foods (like brine shrimp) or regular flake food should be used maybe 1 or 2 times per week. Secondly, mollies really do best in brackish water. The actual salinity doesn't matter all that much, but the combination of higher pH, higher hardness, and raised salinity seems to help them by every relevant marker. A box of marine salt mix like Instant Ocean is what you want (not tonic salt or aquarium salt) and the dosage needs to be around 3.5 grammes per litre upwards (that's about 10% seawater). Other livebearers will thrive in such conditions, as will a variety of salt-tolerant species like glassfish, rainbowfish, and halfbeaks, so finding tankmates for mollies isn't in the least difficult. Thirdly, mollies are sensitive to a neurological disorder called "The Shimmies". Poor water quality seems to be the trigger here. While there's no guaranteed cure, switching from fresh to brackish water conditions seems to help in most cases. All else being equal, these tips will guarantee your mollies are in peak health and should help your unbalanced molly recover. Cheers, Neale.>

Damnation Molly Mom and Her 4 Mo. Old Babies behavior   7/7/07
Hello! In March I wrote to you about my new molly fry and I must say you were extremely helpful. Thank you Tom for all of your insight!
<<Hello again, Bridgette. Glad I was able to help!>>
I currently have 1 female molly, her 11 4 mo. old babies, and 3 new fry in a 10 gal tank. The female ran the male to his death after she gave birth to the first 11 fry she had.
<<I recall this from our last conversation, Bridgette, though it’s often the other way around. You mentioned she was aggressive, though.>>
I am going to buy a 29 gal tank this weekend. Will I need to run this new tank for a month or so before I separate them?
<<The new tank will definitely have to cycle, of course. There are ways to speed up the process, the fastest being the use/addition of BIO-Spira (a Marineland product) which will accomplish this virtually instantly. Not exactly inexpensive but the benefits are pretty obvious.>>
I was thinking of putting females in one and males in another.
<<A good way of heading off a population explosion! :) >>
I know this little tank is overcrowded and need to do something about it right away!
<<Agreed.>>
Also, I've noticed for the last few days that the male 4 mo olds have been looking like they are almost trying to attach to their mother's anal fin. Are they trying to mate with her?
<<A pretty good bet that there’s interest in this regard.>>
Thanks again, as so many people here say, this site is wonderful!
<<Very nice to hear from you again, Bridgette, and thanks again for the complimentary words. Keep up the good work and continued good luck. Tom>>

My golden molly is turning black...  6/12/07
Dear crew:
<Hello.>
I first off want to apologize for my lack of knowledge of fish completely.
<Hmm... not a good start. When caring for any animal, it is always wise to read first, then buy the animal, not the other way around.>
That taken care of, I bought a gold molly to keep my albino... side sucker fish company so he'd have a friend.
<What's a "side sucker fish"? I'm guessing either a Plec (an armour-plated catfish) or a sucking loach Gyrinocheilus aymonieri (a minnow-like fish with a sucker mouth). Either way, appallingly bad choices for neophyte fishkeepers. Plecs grow to around 30-60 cm depending on the species very rapidly and eventually need massive tanks. Sucking loaches also get big (around 25-30 cm) but top that off by being among the nastiest-tempered fish out there. Either way, you will need a tank containing at 200 litres within even the medium term (6-12 months). If you don't have that, return them. One other thing: mollies are extremely delicate when kept in freshwater tanks, and the only sure-fire way to keep them healthy is to keep them in brackish water. Brackish water is unacceptable to both the catfish and the sucking loach. Now, if you feel the need to keep mollies in freshwater despite the fact some or all of them will get sick, you need to ensure the following: Nitrates less than 20 mg/l; pH 7.5-8.2; hardness 20 degrees GH or more. Skipping on any of these is the express route to mollies getting fungus, finrot, and the "shimmies" (a type of nerve damage disease). Don't believe me? Stop by any fish forum you like and review the questions in the Livebearers section. The number of messages about sick mollies will stagger you. I feel I say this every week, but mollies just aren't good fish for beginners and they categorically aren't community fish by the generally accepted meaning of the word. Have a read here: http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm and some of the FAQs as well.>
I've had these fish for about 3 months and all of a sudden my gold molly is turning black, starting with the tail.
<Almost certainly just genetics. Assuming the fish is otherwise healthy and the skin isn't rotting or something. Mass-produced mollies are not "quality controlled" so you have no guarantee they are "pure bred" in any way. So, it's basically a case of enjoy your newly metamorphosed fish!>
I've tried doing some research and I can't figure out if this is just a gold molly turning into a Dalmatian molly (do they do this?)
<With quality stock, no.>
or if it has some sort of problem... in which case I'd like to help.
<No, nothing you can do.>
Thanks!
Jen
<Good luck. Mollies are among my favourite aquarium fish, but they are demanding and they do need special care. It's a shame they're so widely sold, because people assume they're easy fish. But kept well, few fish combine personality, colour, and easy breeding so well. Worth sticking with, and learning about. Cheers, Neale>

Mollies' eating my plastic plants – 06/11/07
Hi,
<Hello.>
A couple of questions for you?
<OK?>
I live in the UK in Devon. I have just started keeping fish, well 12 days ago. I got my first fish a black Mollie and a silver Mollie three days ago. They are doing ok. I have a 35 litre tank, with plastic plants.
<Your tank is probably a bit small for mollies. Bear in mind some species can get to 15 cm in length, if not more, and most of the common varieties in the trade will certainly be in the 5-8 cm bracket when fully grown.>
I have noticed bite marks in the plants. Are they just testing or should I get them some real plants.
<I couldn't imagine mollies actually damaged plastic plants, so that's a first to me. Anyway, they are doing their level best to demonstrate their need for green foods. Use vegetarian "livebearer" flake (NOT generically tropical fish flake except as a treat) plus green foods like Sushi Nori, blanched lettuce, algae wafers, sliced cucumber, tinned peas, etc. Mollies are herbivores in the wild, so try and match that in captivity.>
If I do what plants would you recommend considering I plan to add a small salt content.
<Almost all hard water tolerant plants thrive at the low specific gravity (SG 1.002-1.003) mollies relish. Java fern, Java moss, and Anubias are perhaps the best plants because they come attached to bogwood so are easy to "install" without fussing over substrate. They are also ignored by most herbivorous fishes. Failing these, Vallisneria, Hygrophila, Elodea, Ceratophyllum, Cryptocoryne wendtii all work well in low-end brackish tanks.>
(Not changing over fully just adding the 1tsp per 5ltrs that everyone recommends.
<Don't trust anyone who recommends "spoons per litre" amounts, because it's a meaningless measurement. Once the box of salt is opened, it absorbs water, so over time, each teaspoon contains less and less salt. Ideally, use a hydrometer to measure the specific gravity. A basic floating glass hydrometer will cost about £5. You want about SG 1.002-1.003, or 5-6 grammes of salt per litre. Make up the brackish water as per the instructions on the box, and then measure the specific gravity (SG). Add more water or salt as required.>
Also I have read many articles especially on your site regarding adding a little salt. I plan to do this on the next water change. I have added the salt to the new water and plan to add the water slowly as I refill the tank from the water change. Is this a good idea?
<Adding salt to the water before adding it to the aquarium is exactly correct. Don't forget that any time you top up the tank due to losses from evaporation, *that* water should be freshwater without salt. The salty water is only for water changes.>
Thanks
Doug
<Cheers, Neale>

Black molly question... beh./sys.  4/10/07
Hello WWM,
<Didi>
I just found your website, it looks like an awesome collection! I looked through molly questions but couldn't find anything that answers my particular question, so here it is.
<Okay>
I have a black male molly and a red female swordtail in a small new 3 gallon tank.
<Hard to keep such small volumes stable... do be diligent re maintenance... weekly water changes (maybe a gallon) and careful re feeding>
I bought them a month ago and so far they've been getting along fine, mating and all. The female got pregnant and today started giving birth, and since she has been doing that, the male has been viciously attacking her! I've had mollies and swordtail fish before, for years, and know what they look like when they're horny or mating... and that was not it. The male would charge at the female in short, fast bursts and bite her.
<Likely simple territoriality at play here... not enough room...>
She'd dart away and slam into rocks, walls, etc. It looked pretty bad, so I isolated her in a smaller tank
<! Needs more room, not less...>
to have her babies in peace. Since I did that, the male has been acting normal. She hates the small tank though (about half the size of the other one, so not too small), and is flinging herself at the walls, so I may try to put her back again tomorrow.
I've never had males attack females like that before, in labor or not...
What's going on? I don't want to stress her out and am afraid to bring her back now :( Please help!
Thanks,
Didi
<These fish need at least ten gallons... Bob Fenner>

Mollies beh. – 03/17/07
Hello,
<<Hi, Bridgette. Tom with you.>>
We bought a male and female molly three months ago. Recently the female has been chasing and nipping at the male. Today she had 12 babies and is REALLY chasing him around. What should we do?
<<Isolate the fry, if possible, and try to keep the adults separated. Mollies aren’t “protective” parents like Cichlids are even though it may seem like the female is guarding the babies and she’s also stressed from the birthing process. She needs some recuperation time away from the male. (Sounds to me like she may be more “dominant” than the male anyway and isn’t about to put up with any of his unwanted advances right now.) You might try purchasing a divider for your tank at your local LFS to keep the two apart for a few days. If the fry can’t be isolated, you can try purchasing floating plastic plants for them to hide in or, you can let Nature take its course. For what it’s worth, you can start looking for more fry in about a month or so. Females can store the male’s sperm for months and will continue to become pregnant even without mating during this time. Good luck. Tom>>

Balloon Molly beh.  3/10/07
<<Hi, Lauren. Tom here.>>
I have a balloon molly who has recently been exhibiting some strange behavior.  Every once in a while she turns vertically, with her head pointing straight up.  It appears as if it is done intentionally because it is an extremely fluid movement in which turns horizontally, hangs out for a second or two and then returns to her typical horizontal swimming position with ease.  I have never seen her, nor any of my other balloon mollies exhibit this action.  I know that balloon mollies are odd little fish, but this seems a little too odd. Any suggestions as to what could be causing this behavior?
<<Lauren, I’ve got an Angelfish that does this when it “thinks” it’s feeding time. If I catch the behavior in its entirety, my blood pressure remains normal. When I spot the fish “floating” in this position, my blood pressure jumps about 20 points. A little tough on me and amusing to the fish, I’m betting. Fish, like other animals, tend to be extreme ‘creatures of habit’. They don’t “think” in human terms but can “associate” a behavior with a positive result, typically getting fed. I’d wager that your Molly is going through this routine because it associates it with finding food coming its way. Since it doesn’t display other signs of a swimming impairment, I wouldn’t concern yourself. Just look at it as an “eccentricity”.>>   
Thank you,
Lauren
<<Glad to help, Lauren. Tom>>

My Molly Changed Colors   2/14/07
Hello -
  I have 3 Dalmatian mollies I purchased about 2 months ago.  One was a bit darker than the others but has since turned completely black.
<Happens>
  One of the others is also getting darker, but still has some white spots.  The third doesn't appear to have changed color at all.  Is this normal?
<Not atypical>
I have a few other fish in the tank as well, although the darker molly is surely the dominate
<dominant>
one in the tank, but everyone otherwise appears happy and healthy.  I feed them a varied diet and always add a bit of salt to the water, so I'm inclined to think there are no health issues, but I've never heard of such a thing before.  Is this a common trait with the Dalmatians or an indication of a bigger problem?
  Thanks in advance for your insight!
<Likely not a worry. Bob Fenner>

My Mollies  2/12/07
Hello,
<<Hello, Ashley. Tom here.>>
I recently bought some mollies, like yesterday.
<<We’ll count yesterday as “recent”. :) >>
I bought two Dalmatian mollies (1 male and 1 female) and 1 female Creamsicle molly. I have them in a 10 gallon tank with an angelfish a bit bigger than a loonie (Canadian $1 coin) plus fins and an itsy bitsy catfish which I can't remember what the exact breed is ( I think it started with an "o").
<<The “itsy bitsy” catfish is an Otocinclus. The Angelfish will outgrow your ten-gallon tank just as a “heads up”.>>
From what I've read on the site the male is supposed to be chasing the females around. That seems to be the opposite in my tank. The Dalmatian female is chasing the male around. Is she trying to get him to mate with her?
<<Nope. She’s just more “dominant” than he is. Not “typical” but hardly uncommon.>>
I've looked on both of the females and neither seem to be pregnant at the moment because I don't see a dark spot or anything but I also may have missed it. I'm not the most experienced.
<<None of us were at the start…>>
I also have another question about my Creamsicle one. It seems to be much more active than the other two, not that the others aren't active, the orange one’s just more active, constantly swimming laps around the tank. I read about the whirling disease on your site, could this be an indication of this?
<<Unlikely. Could be a sign of stress, though. Keep in mind that Mollies prefer some salt in their water. I would typify them as a “brackish” water species meaning that they (generally) fall between true freshwater and saltwater. You’ll find folks keeping them across the spectrum regarding salt however, from freshwater to full marine conditions. The sticky part is that your Oto won’t tolerate salt well. What to do? Scaleless fish like your Oto can tolerate minimal amounts of salt. Never more than a ratio of one tablespoon per five gallons of water. On your next water change, pull out about two gallons of water and add about three-fourths of a tablespoon of aquarium salt to the new, conditioned water. This ratio won’t adversely affect the Oto but might calm your Molly down a bit.>>
She still moves around all over the tank but she also tends to backtrack often. So anyway, while the Dalmatians are playing tag the angel just sits around like usual, the cat fish sits in his corner and the Creamsicle swims laps. Can you tell me if they're exhibiting normal behaviour?
<<Neither the Oto nor the Angelfish are particularly active individuals so I’d say their behavior is normal. The Dalmatian Mollies? Once again, their behavior isn’t uncommon. As far as your “Creamsicle” Molly is concerned, let’s see if the salt does the trick for her.>>
Also can anyone tell me how to determine the sex of an angelfish? I've had mine for four months now and have coerced her into being female calling her Morgaine, but I'm still curious if I got it right.
<<Nearly impossible, Ashley, even for folks that are hardcore breeders. The common practice is to select a half-dozen Angelfish and see which ones pair up. From there, the one that lays the eggs is the “girl” fish. Just about the only way to tell.>>  
Thanks a bunch!
Ashley
<<You’re welcome, Ashley. Best regards. Tom>>

Mollies Shaking - 01/27/2007
Hi
<Hello.  Sabrina with you today.>
We have a 40 Lt tank, with guppies and mollies. Most of the fish were born in our tank. Two of the black marble mollies (I think females but they are still a bit small to be sure) have this weird behaviour, they swim to the bottom section of the tank, in the corner and face down they shake their bodies - this can last for about two to three minutes a time and they do it approximately every 5 -- 10 minutes. They appear otherwise healthy, as do the other fish in the tank.
What could be the reason for this behaviour?
<In my experience, this "shimmy" has usually been indicative of a "skin slime" parasite - Costia, Childonella, Icthyobodo....  Other symptoms, though harder to see, would include occasional clamping of the fins and a slight "film" or "cloud" to the skin and fins.  I have also been of the understanding that this "shimmying" can be due to a lack of electrolytes or salts in the water.  If guppies and mollies are all you have, I'd try adding one to two tablespoons of aquarium salt per five gallons of water (12 to 24 grams per 19 liters).  This amount of salt will not be harmful to either guppies or mollies and will actually be quite beneficial to both.  This *may* also help if it is in fact a "skin slime" parasite, but if the symptoms persist after some days, or if the symptoms worsen and the fish get notably "sick", you might consider treating with an anti-protozoan medication.  Of course, this part goes without saying, but I'd better say it anyway:  Be sure to keep ammonia and nitrite at ZERO and nitrate below 20ppm with regular water changes.>
Thanks for the great information you supply on your site.
<I'm glad you've found it useful, thanks!>
Steph
<All the best to you,  -Sabrina>

Molly at bottom of tank   1/23/07
Hi Guys
<LJ>
I have a question about my male Dalmatian molly. First, we goofed up and overcrowded a 5 gallon tank with 2 Dalmatian mollies (1m, 1f) two black big bellied mollies (1m, 1f), and one white big bellied molly. We also have a Pleco, 
<Need much more room to keep one of these>
a catfish, and 4 big snails. We tried having an African Dwarf Frog, but the ammonia levels killed off 1 then because we didn't know what killed it, also the  replacement frog.
While still in the 5 gallon tank, the male Dalmatian molly started swimming at a 60 degree angle, head up. Sometimes it would go completely vertical. He then started just hanging out at the bottom of the tank. Almost lying in the gravel. We were unable to keep the ammonia, nitrate and nitrite levels within healthy bounds, so we got a 20 gallon aquarium and moved them all in there.
<Much better>
He's  still lying in the gravel.
<Takes time... might be damaged>
Sometimes he seems to get a burst of energy and swims  around a for a while. He doesn't seem to have a lot of control, and tends to be  a little "head up". The ammonia, nitrate, and nitrite levels in the new tank are  okay. But, I don't know if there is anything we can add to help the poor guy, or  if he's just gonna die. Any suggestions?
<Patience, time, observation, hope. Bob Fenner>
Thanks
---Linda

Molly behavior - why do they act the way they do?  1/14/07
Good morning WWM crew!
<Good afternoon now...how are you?>
Yesterday I entered into the world of "Molly Hobby". I acquired 5 Mollies and one sucker fish (Jock).
<The latter, is it some sort of Pleco? If so, be aware that the common variety of these can grow to over a foot in length...do be prepared to provide a large tank for him/her...>
The mollies are as follow:
"OJ" (orange M)
"Goliath" (White/Silver M)
"Flo" (Dalmatian F)
"Perdita" (Dalmatian F)
"Baby Pearl" (White/Silver F)
<Sound nice.  If you have space, you may want to add a few more females; I've found a 1:3 or 1:4 male: female ratio to be best, to prevent over-harassment of the females by the males...>
I am fascinated by these fish's behavior! I can sit in front of the tank for hours just watching them.
<They are quite interactive, aren't they? I enjoy watching mine as well...and since they are always looking for food, they seem to "watch" you back, don't they?>
During my observation, I noticed something. The
two Dalmatian girls look to maybe be pregnant...they are a lot 'rounder' than the White/Silver. I research to find out how to tell and of course they should have that black spot...can't really tell w/ the Dali girls.
<Yes, can be hard to tell with the Dalmatian coloration. Generally, when you have both male and female livebearers in a community tank, the girls will likely be pregnant...that's what these fish do!>
The white one should be obvious and there are no darker areas on her.
<She may be "early-stage" pregnancy.  All you can do is wait and see; molly gestation period is about 4-6 weeks. Again, my bet is on all the girls in your tank are indeed preggers...they virtually always are!>
Once all the fish became 'comfortable' in the tank they started moving around. It seemed the two Dali girls were trying to get the attention of the two males but they didn't want anything to do with them.
<Interesting - it's usually the opposite!>
Instead, both the boys were after the white F.
I saw both the males mate several times and can't seem to get enough. The two boys even pick at each other. All this is
happening with the Dali girls being left out. So, what is so special about "Baby Pearl"?? Sometimes she likes the attention and other times she seems annoyed; in addition, the two dalis seem to 'protect' her sometimes and they seem to be jealous other times.
<I can't tell for sure what the fish are "thinking", but again, if you have room, increasing the amount of females in the tank should help re-direct some of the males' attention.  Perhaps the two "left out" girls are already pregnant, and the little female is not, so the boys are trying to change that? Or, something in Baby Pearl's temperament attracts the boys...can't tell you for sure.  Just make sure to provide lots of cover in the form of plants, decorations, etc., so that any one molly can "retreat", if need be.>
My sister, an advanced hobbyist, really couldn't come up w/ anything except the two dalis are already pregnant and "Baby Pearl" is a virgin so to speak!!!
<That's what I'm thinking...but it truly is just an educated guess.>
Please help me understand my mollies behavior!
<I'm not sure anyone really "understands" fish behavior completely; it's likely natural selection, Darwinism at work...>
Thanks,
Stephanie
<Stephanie, the only thing I can suggest is altering the male: female molly ratio a bit, to spread out the aggression of the males a bit.  Again, this is assuming the tank is large enough and not already fully stocked...
Enjoy your mollies - they are fun little fish!
Best regards, Jorie>

Molly Gender Changing   12/6/06
Hellow WWM crew!
I used to have a few mollies, and I have a very strange question about one of them.
We went to a pet store, and I'm pretty sure we bought a girl Molly. (The guys have this little stick fin thingy, and the girls just have regular fins.)
<Ah, yes>
Well, we got home, and she was so fat, she almost looked pregnant. Well, about a week later, I noticed some spots on her. I didn't think it was such a big deal. So the next day or so, we went on vacation to Florida. By this time, the fish was half covered with spots. So when we came back 2 weeks later, the fish had changed into a boy! Or at least I think it was a boy!
<Mmm, yes... happens>
She had spots everywhere, and she was a BOY! I even caught her trying to mate with other girls, and if I'm right, got one of them pregnant. Is it common or at all possible for a fish to just change genders like that, or do you think maybe he was a boy the whole time?
<Could be either... not uncommon.>
I'd love to know! (The fish is dead now...been dead for 2 years...just thought I might add that on.)
Any help is appreciated! Thanks WWM crew!
-Leira
<Want to be further astounded? Look up "Amazon Mollies"... Bob Fenner>

Molly Mayhem  11/21/06
Hello,
<Hi>
I stumbled on your site, looking for an answer to my question, and could not find it, so, so I am asking...
<Ok>
I bought two Dalmatian Mollies about a month ago, and added them to a 55 gal tank with Neons, two Powder Blue Gourami's, one Silver Shark, and two Dinosaur Eels.... ok, now before you tell me, yes, I know the Eels should not have been in there, and we found this out by losing a few fish, they have since been separated into another tank of their own....
<Several of the remaining fish come from very different environments and require different water conditions, check out WetWeb for specifics.>
Anyway... before our Eels got really "hungry" all of a sudden, our female Dalmatian looked as if she were getting quite plump, so we thought we were going to have fry soon... then our eels did their thing, and we lost our male Dalmatian, a few Neons, and two blood gourami's, and a powder blue Gourami... after this happened, and we removed the eels immediately, our one powder blue, and our female Dalmatian started acting like they were really confused, they would swim all over the tank, very rapidly, as if they were
"looking for something" during this time our female Dalmatian seemed to "lose" her plumpness, and we just wrote it off that she was not pregnant, because she never got big enough to "drop"... <Not uncommon, she probably either gave birth prematurely or aborted the pregnancy altogether.>  So we went and bought another powder blue Gourami, and another male Dalmatian, and added them to the tank.  Both "stressed" fish calmed right down, and "buddied" up to their new friend... and we seem to have happy fish again, (and our silver shark is now growing, which he wasn't doing before)... but the main question I have is this... now it seems that our female is getting quite plump again, and the male and female, who were getting along great, now are exhibiting behavior I do not understand. I read that when a female molly is pregnant, she will irritate others in the tank <Depends on the individual>, but this is not the case, it is quite the opposite, the male molly follows her constantly, seeming to "smell" her rear side <Trying to mate.>, and she is constantly trying to swim from him. He does this all the time, seeming to give her no peace at all... what is the deal with that?  <Need to have more females than males to give the ladies a break from the very determined suitors.>  
She is not bothered by any of the other fish, they all seem to get along very well, we still have the two powder blues, 3 Neons, the two Dalmatians, and the shark, along with a plecostomus. I was trying to look for the black spot they speak of, and the problem is that she is so dark black, with Dalmatian spots, that we can't tell... any help?
Thank you,
Kathy
<You can assume she is pregnant, they almost always are if they are in contact with a male within the last 6 months.  The harassment is normal, and can be lessened by adding more females if the tank size allows.  You need to review the requirement of your various fish for incompatibilities and the long term problems that will develop from them.>
<Chris>